Patent · US Expired

Method of multi-level storage in DRAM

US5283761A · kind A · utility

171Cited by
5References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 22, 1992
Grant dateFeb 1, 1994
Priority date
Expiry dateJul 22, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C2211/5634
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A method of processing data having one of four voltage levels stored in a DRAM cell is comprised of sensing whether or not the data voltage is above or below a voltage level midway between a highest and a lowest of the four levels, setting the voltage on a reference line higher than the lowest and lower than the next highest of the four levels in the event the data voltage is below the midway voltage level, and setting the voltage on the reference line higher than the second highest and lower than the highest of the four levels in the event the data voltage is above the midway point, and sensing whether the data voltage is higher or lower than the reference line, whereby which of the four levels the data occupies is read.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.